It's been a few years, but last time I was on the Pikes the National Trust were busy repairing one of the paths up by Harrison Stickle, vigorously pursuing their policy of making it easy for people who shouldn't be up there to get up there and either get lost or have accidents or both. Once on Helm Crag I passed a young couple- she was wearing a light Summer dress and "fashion" sandals.... the mist rolled in about an hour later, and the temperature dropped from 22 to less than 10 degs.